Apparatus for the production and exhibition of colored photographs.



T35@ mm G. J. DRAG. APPARATUS FOR THE PRODUCTION AND EXHIBITION OI COLORED PHOTOGRAPHS.

APPLIOA'IIOI FILED HAY 26,1905.

905,802. Patented Dec. 1,1908.

2 SHEETS-SHEET l.

Search C. J. DRAG. APPARATUS FOR THE PRODUCTION AND EXHIBITION 0P COLORED PHOTOGRAPHS.

APPLICATION FILED MAY 25,1905.

Patented Dec. 1, 1908.

2 SHEETS-SHEET 2.

UNITED STATES PATENT oEEroE.

CHARLES JULIUS DRAG, OF WAR-SAW, RUSSIA.

APPARATUS FOR TI-EE PRODUCTION AND EXHIBITION OF COLORED PHOTOGRAPHS.

To all whom it may concern.

Be it known that 1, CHARLES JULIUS DRAG, a sub'ect of the Emperor of Russia, residing at arsaw, Russia, have invented certain new and useful Improvements in Apparatus for the Production and Exhibition of Colored Photographs, of which the following is a specificat1on.

This invention relates to improvements over the invention described in my application Serial No. 192,842, filed February 9, 1904 for the production of three )ictures of ari object in the three primary colors.

The object of the invention is to simplify the arrangement of the camera, more particularly the arrangement of the main part thereof, namely the system of prisms which allows of dispensing with the use of color filters.

The novelty resides in the peculiarities of construction, and the combination and arrangement of arts hereinafter more fully described and dlaimed.

The invention is clearly illustrated in the accompanying drawings which, with the characters of reference marked thereon, form a art of this specification and in which:

igure 1 is a view illustrative of the invention. Fig. 2 is a diagrammatic view of a five lens system. Figs. 3, 4, 5 and 6 show similar views of different arrangement embodying the principle of the invention. Fig. 7 is a detail in end view and longitudinal section.

Like characters of reference indicate like parts in the several views.

The method for simplifying the system, to which the present invention relates, is based on the fact, that by a special arrangement of the central lens-system b and c fulfilling certain conditions which will be stated hereinafter, the number of prisms in each branch of the system can be reduced from four to two, the optical correction of the whole being nevertheless preserved.

The ap aratus is provided in front of the lens 0. witfi a diaphragm .9 (Figs. 2 to 6) which renders parallel the main rays R R R and so on before they enter the prism A.

For the purpose indicated the separate parts of the system must have fixed relative positions. The synthesizing )rism-sets cannot, therefore, be displaced for the purpose of dividing the beam into three beams of equal actinic power corresponding to the different degree of intensity of the plates, and it is in this case necessary to use auxil- Specification of Letters Patent.

Application filed May 25, 1905.

Patented Dec. 1, 1908.

Serial No. 262,293.

iary devices such as can also be employed in apparatus comprising four prisms. These devices may consist of small mirrors or prisms producing total reflection mm Figs. 2, 3 and 4. The purpose of branching off the beams in three directions in the optical system can also be effected by deflecting the rays by means of small refractive prisms p, 7) Fig. 5. Since these small prisms have very small indices of refraction, the aberration due to their use is negligible. For producing larger deflections it is, however desirable to make these small prisms achromatic, or to neutralize the effect of each small prism 11 (Fig. 6) by an opposite effect due to small prisms g introduced into the rearward branches of the system (Fig. 6). For the same purpose the refractive index of the fourth prisms D D Fig. 6 can be increased. VVit-h the aid of these devices and by repeatedly deflecting the optical axis of each system, the pictures can be given any desired positions as regards the distances by which they are separated from each other and they can also be brought into one plane for the purpose of being focused on a single panchromatic plate. This latter position 1s particularly useful when the purpose of the apparatus is reversed, that is to say, when instead of making three complementary negatives of an object, a projected image in natural colors is obtained, by synthesis, from three complementary colorless positives. The fixing of all three pictures on a single panchromatic plate facilitates in this case the obtaining of uniformity in the exposure to a powerful source of light required for the projection, and obviates the inconvenient centering of the separate pictures. This is more particularly important for the projection of. a series of successive pictures, for instance when the apparatus is used in combination with a kinematograph.

If the picture in natural colors is not to be thrown on to a distant screen but directly on to the retina of the observer's eye, the latter being placed against the front objective, the optical composition of the picture will not correspond to the normal conditions of accommodation, for which the human eye is ada )ted, that is to say, the picture will not be suitable for unaided sight, since the rays converge on leaving the front objective. To convert the converging rays into diverging rays, a dispersive lens 1 (Fig. 7) can be arranged at the front of the earch Room apparatus, and this lens may be provided with a conical tube t to screen the eye from Having thus described my invention What I claim is:

1. Means for the production of colored photographs without the employment of color filters, comprising grou s of rearward synthesizing risms a multip e lens system, common to al of the pictures, and the central part of which forms the analyzing prism device, one of said lens systems constructed to direct the ray pencils through said rearward synthesizing risms.

2. Means or the production of colored photogiaphs without the employment of color ters, comprising grou s of rearward synthesizing risms a multip e lenssystem, common to al of the pictures andthe central part of which forms the analyzing prism device, one of said lens systems constructed to direct the ray pencils through said rearward synthesizing prisms, and separate identical optical systems.

3. Means for the production of colored photographs without the employment of color filters, comprising grou s of rearward synthesizing risms a multiple lens system, common to al of the pictures and the central part of which forms the analyzing prism device one of said lens systems constructed to direct the ray pencils through said rearward synthesizing rism, and means for optical correction in ependent of the said lenses.

4. In means for the production of colored photographs a telescopic achromatic lens system of multiple lenses having a common inner focal lane, the separate parts of the system having fixed relative positions, and

auxiliary devices for producing total reflection.

5. In means for the production of colored photographs, a telescopic achromatic lens system 0 multiple lenses having a common inner focal plane, the separate parts of the system having fixed relative positions, and auxiliary devices for producing total reflection and'prisms introduced into the rearward branches of the system.

6. In means for the production of colored photogra hs, a telescopic achromatic lens system ol multiple lenses having a common inner focal plane, the separate parts of the system having fixed relative positions, and auxiliary devices for producing total reflection and prisms introduced into the rearward branches of each system.

7. An 0 tical apparatus for producing a plurality o complementary negative images of an object and inversely for the optical synthesis of a projected image in natural colors from a plurality of complementary colorless positives, dispensing with colored media, comprising an optical system common to all the images and consisting of a double system of lenses separated by a highly dispersive analyzing set of prisms, an aperture shutter in the front focal plane of the objective, and

three separate identical 0 tical systems,

each consisting of a lens, an a set of highly dispersive synthesizing prisms, each set having a symmetrical position to the said analyzing set of prisms.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES JULIUS DRAG.

Vvitnesses 1 WITHOLD BIADORUKRIEG, HEINRICH H. KAISER. 

